This Zebra Shark Had Babies Without the Help of a Male

A zebra shark that hadn’t been in contact with males for years gave birth to three healthy pups.

Aquarists at The Reef HQ Great Barrier Reef Aquarium in Townsville, Australia reported that the captive zebra shark laid 41 eggs, 3 of which hatched. Named “Leonie” and in her twenties, she’s now one of the main attractions at the aquarium.

The so-called “virgin birth” is quite rare, but has been documented in fish, snakes, and various invertebrates.

Shark expert George Burgess of the Florida Museum of Natural History said, “We have seen this process, called parthenogenesis, in a number of shark species, particularly in aquaria… I think it happens when they get pushed into an evolutionary corner, like in an aquarium with no males around.”

Scientists first presumed that this phenomenon occurred because females stored sperm from previous encounters with males, but this was disproven after several other sharks gave birth to pups that had never had access to males.

Zebra shark egg cases

To fully prove this, scientists test the DNA to confirm that it only contains material from the mother.

Leonie had lived with a male partner before and had previously given birth, but scientists believe the lack of genetic diversity in her latest offsprings’ DNA suggests that they came from just her. Because of the lack of genetic variation, the offspring are probably less fit and more vulnerable to diseases.

Although this shift from sexual to asexual reproduction has been seen in a Colombian rainbow boa and a spotted eagle ray, this is the first time it has been observed in a shark.